(a) Field of Invention
The present invention relates to a fire alarm control system embodying a single switch capable of silencing local alarms and preventing the transmission of a remote alarm and further being capable of resetting the system.
(b) Description of Prior Art
To date, commercial and residential fire alarm control systems use separate control switches for the "reset", "alarm silence" and "remote station disconnect" functions. Fire alarm control systems have latching circuitry to lock in an alarm signal for the needed time whether the detection device itself stays latched in or just gives a momentary signal as in the case of some heat detectors. Systems using smoke detectors stay latched in alarm electronically with a visual indication after detecting smoke. This makes it possible to determine which unit triggered the alarm in cases of false alarm or little smoke where the cause is not obvious. Most fire alarm systems sound audible signals such as bells or horns since warning occupants of the fire danger is usually the system's main purpose. These audible signals need to be silenced once the warning has been given. The control system circuitry and the smoke detector need to be reset, ready to work again, but only after the source of the alarm has been identified. Hence, known systems provide at least two switches, one to silence and one to reset the system. The silence is generally a two-position switch and the reset is usually a momentary switch of the push-button or spring return type. In addition, systems connected to the fire department or a remote central monitoring station require a third switch to disconnect this alarm output to the remote station for testing, fire drills or repairs.
With this type of switching as utilized in the prior art, if the operator gets confused, he may reset the system while attempting to silence the alarm and lose the information giving the origin of the alarm.